Forward Error Correction Design for AM IBOC Digital Audio Broadcasting

For hybrid In-Band-On-Channel (IBOC) systems that broadcast digital audio programs simultaneously with analog Amplitude Modulation (AM) programs in the AM bands, bandwidth and transmission power are extremely limited. This paper investigates that tradeoffs between performance, complexity and delay of three such schemes: Reed-Solomon (RS) coded QAM, trellis coded modulation (TCM) and serially concatenated TCM using turbo decoding principle (SCTCM). We shoe that by using SCTCM, efficient modulation scheme can be obtained, with the price of increased block length and complexity. However, since decoding delay is not critical for digital audio broadcasting (DAB), SCTCM is a viable choice for these systems. We also compare the performance of the less complex TCM schemes with that of the RS coded QAM schemes.